Subminiature motors serve, inter alia, to drive mini-fans. The latter serve, for example, to cool processors in computers, for equipment cooling in small equipment, etc., and they have very small dimensions. For example:                fans of the ebm-papst 250 series have dimensions of 8×25×25 mm;        those of the ebm-papst 400F series have dimensions of 10×40×40 mm;        those of the ebm-papst 400 series have dimensions of 20×40×40 mm; and        fans of the ebm-papst 600 series have dimensions of 25×60×60 mm.        
The power consumption of such fans is 0.2-0.6 W for the 250 series, 0.6 to 0.9 W for the 400F series, and 0.4-3.0 W for the 400 and 600 series. Their weight is, for example, approximately 5 (five) g for the 250 series, between 17 g and 27 g for the 400/400F series, and approximately 85 g for the 600 series.
In motors of this miniature size, which must be very inexpensive, it is important to make assembly as simple as possible, so that the highest possible degree of automation becomes possible during manufacture. Only extensive production automation makes possible the uniform quality that is a prerequisite for a long average service life.
A further complicating factor with such subminiature motors is that their components, entirely analogously to those of a mechanical clock mechanism, are very delicate and therefore not very robust. The rotor shaft, for example, is often only as thick as a knitting needle and can therefore easily be bent if handled carelessly, rendering the motor unusable. This danger exists in particular during assembly.
With such very small motors, automated production is difficult and often requires additional manual work. This applies especially to the connection of elements of the winding arrangement arranged on the stator lamination stack to the associated circuit board. As shown by FIG. 10 below, metal pins that are secured in an insulator which is located on the stator lamination stack have hitherto been used for this. Such pins are pressed, in a separate working step, into holes in the plastic of the injection-embedded lamination stack. They are called “Autosplice” pins.
A metal pin of this kind has one wire end of the winding arrangement of the motor wound around it, and is introduced, through an opening, into the circuit board and then soldered thereto. This method reaches its limits, however, at a maximum wire diameter of approximately 0.24 mm, since with thicker wires a pin of this kind bends, or the orifice in the insulating material of the injection-embedded lamination stack becomes enlarged and destroyed.
In such cases, it is then possible, for example, to solder the enameled copper wire manually onto solder pads of the circuit board. In another method, so-called insulation displacement contacts are used, but, for this, the wire diameter must be greater than approximately 0.17 mm.